1. Field of the Invention
The present invention relates generally to automated test equipment and, more specifically, to wire testing systems and methods.
2. Description of the Related Art
Automated test equipment (ATE) is computer-controlled equipment that tests electronic devices for functionality or performance. One category of ATE includes automated wire testing machines for testing cables, wire harnesses and other complex wired assemblies. Wire testing machines are also variously referred to in the art to which the invention relates as wire testers and wire analyzers.
The term “wire harness” or “wiring harness” is commonly used to refer to an assembly comprising a bundle of electrical cables with electrical connectors at their ends. Some wire harnesses, such as those used in aircraft, ships, mass transit vehicles and other large vehicles, can be quite large and complex, comprising many individual cables of various lengths, with various types of connectors. Each cable may have many individual wires bundled together that terminate in a connector having a corresponding number of contact pins or receptacles (sockets). The connectors themselves can be quite complex, such as the cylindrical connectors commonly used in military and aerospace vehicles, which typically have from a dozen to well over 100 contacts housed in cylindrical shell with a male or female bayonet or threaded coupling mechanism. Wire harnesses can have myriad network-like topologies, as may be needed to route signals throughout a vehicle or other large system, with branches and sub-branches of various lengths terminating in connectors at various locations.
As illustrated in FIG. 1, testing a typical wire harness 100 presents several challenges. The front panel of a wire testing machine 102 typically has a number of tester interface connectors 104, which may be all of the same type or of several different types. Nevertheless, the connectors of the wire harness to be tested (i.e., the “unit-under-test” or “UUT” 100) may be of still another type that cannot be mated with those of the wire testing machine 102. Also, a wire harness having a combination of some very long cables 106, perhaps extending on the order of ten meters or more, and some much shorter cables 108, is generally unwieldy, making it inconvenient to have all of the connectors 110 of all of the cables plugged into the wire testing machine 102 simultaneously. For these reasons, personnel charged with testing a wire harness typically construct one or more adapter cables 112. An adapter cable 112 will have a connector 114 at one end that mates with a connector 110 on the UUT 100 and a connector 116 at the other end that mates with a tester interface connector 104 on the wire testing machine 102. Each adapter cable 112 can be made as long or as short as may be convenient to extend between the wire testing machine 102 and the point along the length of the UUT 100 at which the corresponding connector 110 is found. The set of one or more adapter cables 112 is specifically designed for the testing of a corresponding wire harness 100 and generally cannot be used to test other wire harnesses having other structures or topologies. Thus, a manufacturer that produces, for example, 25 different wire harnesses, may have 25 corresponding sets of adapter cables 112 for testing them on the manufacturer's wire testing machine 102.
It would be desirable to test complex wire harnesses on a wire testing machine without having to construct, store and use equally complex, cumbersome an d specialized adapter cables. The present invention addresses these problems and deficiencies and others in the manner described below.